Inkjet printers typically utilize a printhead that includes an array of orifices (also called nozzles) through which ink is ejected on to paper or other print media. One or more printheads may be mounted on a movable carriage that traverses back and forth across the width of the paper feeding through the printer. A printhead may be an integral part of an ink cartridge or part of a discrete assembly to which ink is supplied from a separate, often detachable ink container. For printhead assemblies that utilize detachable ink containers, it is important for the user to position the container correctly during installation to establish a good connection between the container outlet and the printhead assembly inlet and thereby ensure that ink will flow properly from the container to the printhead(s). Also, the user must remove the shipping cap that covers the outlet of a new ink container before installing the container in the printhead assembly. While this might seem obvious, the process of installing an ink container can be difficult for users who are not familiar with this type of inkjet printing system, particularly for those users who may not always read and follow installation instructions that accompany the products.